Field of the Invention
The present invention relates to a method of modeling a haptic signal from a haptic object and a display apparatus. More particularly, the present invention related to a method of modeling a haptic signal from a haptic object and a display apparatus, which realize a tactile sense having a shape and a texture of a haptic object.
Discussion of the Related Art
Touch panels are a type of input device that is included in display apparatuses such as liquid crystal display (LCD) apparatuses, field emission displays (FEDs), plasma display panels (PDPs), electroluminescent displays (ELDs), electrophoretic displays (EPDs), and organic light-emitting display apparatuses. Touch panels enable a user to input information by directly touching a screen with a finger, a pen or the like while looking at the screen of a display apparatus. Touch panels have been commercialized as input devices for portable information devices, such as smartphones, tablet personal computers (PCs), etc., and various electronic devices such as notebook computers, monitors, televisions (TVs), etc.
Touch panels are categorized into a resistive type, a capacitance type, an infrared type, etc. depending on a touch sensing method. Recently, since the capacitance type provides convenience in a manufacturing process and is good in touch sensitivity, the capacitance type is attracting much attention. Capacitive touch panels are categorized into a mutual capacitance type and a self-capacitance type. Mutual capacitive touch panels realize a multi-touch input, unlike self-capacitive touch panels.
Recently, haptic technology that applies an electrical tactile stimulus to a skin of a person by using an electric field (or a friction force) is being developed along with touch technology. Display apparatuses to which the haptic technology is applied apply a haptic signal to a haptic electrode to generate an attractive force for stimulating a tangoreceptor of a human body, and stimulate a tactile sense of a user by using the attractive force, thereby enabling the user to recognize a touch and a texture of the touch.
However, since display apparatuses to which conventional haptic technology is applied apply the same haptic signal to haptic objects having the same shape, haptic objects that have the same shape but have different materials cannot provide tactility of the materials to a user.
For example, FIGS. 1A and 1B are diagrams showing haptic signals respectively corresponding to haptic objects having different textures in a display apparatus to which conventional haptic technology is applied. FIG. 1A shows a haptic signal corresponding to a first haptic object 1 of a plastic material having a prism-pattern texture object 1a, and FIG. 1B shows a haptic signal corresponding to a second haptic object 2 of a rubber material having a prism-pattern texture object 2a. 
As seen in FIGS. 1A and 1B, the display apparatus to which the conventional haptic technology is applied generates haptic signals respectively corresponding to shapes of the texture objects 1a and 2a irrespective of materials of the haptic objects 1 and 2 and provides tactility of the haptic objects 1 and 2 to a user. Therefore, the haptic objects 1 and 2 have different materials, but fingers of the user feel the same tactile sense from the haptic objects 1 and 2 that respectively have the texture objects 1a and 2 having the same shape.
For this reason, the display apparatus to which the conventional haptic technology is applied cannot realize a tactile sense having the same shape and texture as a texture object of a haptic object.